Create ActivityClientRecord early in preExecute

We can guarantee that LaunchActivityItem will queue before
ActivityConfigurationChangeItem.
But ActivityConfigurationchangeItem#preExecute() still has the
opportunity to execute before LaunchActivityItem#execute(). And at this
time, ActivityClientRecord has not been created.

This CL create ActivityClientRecord early in
LaunchActivityItem#preExecute() and store in a new list of
ActivityThread. Thus others can guarantee to get the
ActivityClientRecord in preExecute().

Bug: 187691892
Test: atest TransactionExecutorTests
Change-Id: Ib40270345223c5c6e76333803faf98937c5527f9